Tri-O-formylcholic Acid is an intermediate used in the synthesis of 3α,7α,12α-Trihydroxycoprostanic Acid-d3 (T795157), which is a labelled analogue of 3α,7α,12α-Trihydroxycoprostanic Acid (T795155), a precursor of Cholic Acid (C432600), it undergoes side chain oxidation during the synthesis of bile acids. It was found that Zellweger’s syndrome patients have abnormal mitochondrial structure, the organelle that is responsible for the side chain oxidation, and as a consequence, excess amounts of 3α,7α,12α-Trihydroxycoprostanic Acid.